The present invention relates generally to network apparatus for control of power-on/off of electrical equipment including digital computers, and more particularly to network devices adaptable for use in establishing local area network (LAN) connections between or among a plurality of computers associated.
In the recent years certain hardware devices and software application software programs are commercially available which are capable of providing access to a remotely located computer at a far cite for causing a required software program prestored therein to get started or of transferring data files stored in such remote computer, such as for example an electronic-mail (E-mail) or document data. In such an event, however, any remote access to such computer is unachievable if the remote computer being accessed is rendered physically inoperative in the power-off state. More recently, advanced computers are commercially available from some leading companies, including IBM Japan Corp., which offer capabilities to remotely control power-on/off of any one of remote-cite computers by giving access thereto via public telephone communications links. Such computers of this type are remotely controllable in power-up/down in a way such that these are automatically rendered operative or xe2x80x9cwake upxe2x80x9d upon receipt of a certain signal such as encrypted number data via an associated telephone interconnect line. After power-up of these computers, any one of their xe2x80x9cnativexe2x80x9d functionsxe2x80x94typically, unmanned telephone answering, and automatic facsimile receptionxe2x80x94become remotely controllable and then usable to users at remote cites.
Unfortunately, the approach to such enhanced usability based on the xe2x80x9cwake-on LANxe2x80x9d architecture described above does not come without accompanying a penalty: as the connectivity of computers to the public telephone interconnect network increases upon receiving of remote-controlled xe2x80x9cwake-upxe2x80x9d requests, so does the chance for illicit access to such computers by unauthorized persons. As computers are increasingly employed in wide area networks including the xe2x80x9cInternetxe2x80x9d, illicit access to office-use and/or home-use personal computers (PCs) increases in number. One approach for providing the security by protecting these computers against any unauthorized access attempts via communication links is to employ secure management of password data as required when giving access to target computers. Another approach is to install a security gateway unit generally called the xe2x80x9cfire wallxe2x80x9d at a selected xe2x80x9chubxe2x80x9d location of the network infrastructure used.
However, the prior known remotely power-on/off controllable computers are inherently designed to merely accommodate automatic telephone answering and facsimile data reception functionalities, and thus are not aimed at accommodation of digital computer communications systems such as LANs or equivalents thereto. Hence, even where one xe2x80x9cnetworkedxe2x80x9d computer is electrically powered on by the online remote control procedure, it still remains impossible to permit the intended software program stored therein to get started, or unattainable to send forth any intended E-mail or document file stored therein unless otherwise a special-purpose software program with specific functions of communications protocol adapted for use with the network is separately prepared and installed in such computer.
Another problem encountered with the prior art approaches lies in deficiency of security upon remote access to network computers. Most prior computers are designed so that all of their internal units or modules are not completely powered off in a wait or xe2x80x9csleepxe2x80x9d mode prior to startup under remote control. A central processing unit (CPU) or microprocessor of each computer is set in sleep mode with reduced power dissipation. This means that the CPU is in the state waiting for reception of any possible signal input thereto, and thus can still consume certain amount of electrical power. This would result in unintentional permission for the CPU to be illicitly remote-accessed by unauthorized users, which in turn reduces the computer security.
It would be appreciated to those skilled in the computer art that there are no absolute or xe2x80x9cidealxe2x80x9d schemes for perfectly preventing any possible unauthorized access to computers and networks. In such circumstances, an enhanced security system with multiple levels of security must be employed in order to reduce or minimize the risk of illicit access attempts by unauthorized users to network computers.
It is therefore an object of the present invention to increase the security of computers linked via communication lines while accompanying online power-on/off controllability for remotely located computers and also offering required functions adaptable for use with a chosen communication protocol in a communications network used.
To attain the foregoing object the present invention provides a remote network device operatively coupled to a microprocessor, more than one hardware resource connected to the microprocessor, a xe2x80x9cmainxe2x80x9d power supply for supplying power to the microprocessor and hardware resource, and an external communication network. The device includes a switch module provided on a power supply line coupling the power supply to the microprocessor and the hardware resource, for performing a switching of the operation voltages of the microprocessor and the hardware resource. The device also includes a stand-by module disposed on a signal transmission line coupling the microprocessor and hardware resource to an external communications network. The standby module has its own drive power supply independent of the main power supply, and is normally rendered operative. The standby module is comprised of an identifier unit and a controller unit. The identifier is for identifying at least one of ID information and password information being added to a signal as received from the external communication network. The controller is operatively responsive to an identification result of the identifier, for controlling the switch module to thereby control the switching of the operation voltages.
In accordance with one aspect of the instant invention, the remote network device further includes a control unit responsive to an identification result of the identifier unit, for selectively switching the operation voltages of a plurality of hardware resources.
In accordance with another aspect of the invention, the stand-by module is operable to recognize operation voltages of the microprocessor and hardware resource in fixed time intervals, wherein the standby module comprises recognizer unit for controlling the switch module in deference to a recognition result to thereby control switching of the operation voltages, and transfer unit for externally transferring a recognition result of the recognizer.
In accordance with still another aspect of the invention, after turning on the operation voltages of the microprocessor and the hardware resource in response to a signal as received from the external communication network, ID information and password information are generated for addition to a transmission signal, which are different from one or both of the ID information and password information that have been added to the signal received.
In accordance with a further aspect of the invention, the remote network device preferably includes therein an encryption/decryption processing unit for encrypting a transmission signal being sent externally and for decrypting an encrypted signal received externally. This may prevent the contents of transmit/receive signals from being leaked to unauthorized persons.
In accordance with a yet further aspect of the invention, a network involves more than one or preferably a plurality of computers each of which has a built-in remote network device configured as stated supra.
These and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings.